#yuki_9
import heapq

n=int(raw_input())
a=map(int,raw_input().split())
b=map(int,raw_input().split())
heapq.heapify(a)
a=[[i,0] for i in a]

aa=a[:]
for i in xrange(n):
 aa[0][0]+=b[i]/2
 aa[0][1]+=1
 heapq.heapify(aa)
res=0
for i in xrange(n):
 res=max(aa[i][1],res)
print res